The general long-term goals of this project are to develop new methods for the analysis of the structure and dynamics of biomacromolecular systems and to use these methods to provide insight at the molecular level into biologically relevant properties of these systems. The principal technique to be used is vibrational spectroscopy, and the principal systems to be studied are lipid bilayers and lipid-related model systems. A computational method for simulating the infrared and Raman spectra of an assembly of disordered chain-molecules, such as exists in the hydrocarbon component of a lipid bilayer, will be developed. This method, which is an extension of that recently developed in our laboratory for liquid n-alkanes, after testing with observed spectra, will significantly extend the current range of applicability of vibrational spectroscopy to the diagnosis of lipid bilayer structure. Another new method to be developed is designed for the study of the microaggregation of the components in a mixed-lipid bilayer in its gel state. This method, which exploits crystal band-splitting in infrared spectra and which has already been used in our laboratory to study microphase segregation in binary n-alkane mixtures, can be used to measure lipid domains of 1-100 molecules, sizes much smaller than is accessible to any method currently available. The spectral simulation method and the microaggregation method will be used, in conjunction with theory and with other experimental techniques, to study molecular structure and molecular motion in phospholipid bilayers and lipid-related systems.